For thousands of years, man has tried various methods to communicate with groups of people, in classrooms, meetings and large groups. For most of the time, a speaker used his voice and hand movements to communicate with his audience. But this had it limitations, particularly in regards to technical data. So the next step was to use paper charts and diagrams that the speaker could flip through to provide his audience with detailed data. This had the problem of being particularly bulky and difficult to move between locations.
The next advancement involved the use of overhead projectors and foil slides. For most of the latter half of the twentieth century, most meeting rooms contained an overhead projector. These projectors contained a high wattage light bulb below a flat topped lens. The bulb projected light through the lens and through the speaker's foil. The light then traveled through another set of lenses and a mirror, that turned the image 90 degrees for projection onto a screen or other surface. The speaker prepared a set of foils that contained his presentation information. These foils were either hand drawn or printed on a laser printer.
This method had the disadvantage that the slides were not easy to change on the fly, and could be hard to rearrange in the middle of a presentation. As a result, there was a great need to find a more convenient method of directly projecting presentations onto a screen.
The solution came in the form of LCD projectors. These projectors connected directly to the computer, typically using the external monitor port on the computer. The computer generates the image and transfers the image to the projector. The projector then uses a high powered bulb to convert the image into light. The white light from the bulb is split using dichroic mirrors into red, green, and blue light beams that are directed to small LCDs that allow or disallow portions of the light beam to proceed to a dichroic combiner cube. The dichroic combiner cube reassembles the red, blue and green light beams into a combined beam. This is then projected through a lens to the screen or wall.
However, these devices have the disadvantage of being heavy and bulky. Even the best devices weigh 2-4 kilograms (roughly 4-8 pounds) and can take up the volume of a ream of paper. A lighter and more portable solution is needed. Something of a size and weight that can easily be carried in a pocket or a briefcase. But the current technologies cannot be made small enough to fit in such a package. This invention addresses the abovementioned problem.